With the development of society and the increasingly popularization of electronic products, people's demand for an energy storage device is becoming higher and higher, and thus currently it is a key problem to improve the energy density, prolong the service life and reduce the material production cost of the energy storage device.
Currently, the cathode materials of commercial lithium-ion batteries mainly include a series of lithium-containing transition metal oxides such as lithium manganate, lithium cobaltate, and lithium iron phosphate. However, the specific capacities of those materials are less than 300 mAh·g−1 which limit the power storage capacity of those materials seriously. As an active ingredient of a lithium-sulfur battery in a new energy storage system, the theoretical specific capacity of elemental sulfur can be up to 1675 mAh·g−1. But since the elemental sulfur is an insulator, it is necessary to complexing the elemental sulfur with a highly conductive substance to meet the requirements of electric conduction. Furthermore, an intermediate product polysulfide formed during the charge and discharge of a sulfur-containing electrode can dissolve in an electrolyte and migrate to a negative electrode under the action of a concentration gradient to cause an irreversible loss of sulfur, thereby finally resulting in a sharp drop of the power storage performance of the sulfur-containing electrode.
In order to improving the electrochemical performance of the sulfur, various hierarchical structured conductive materials have been thoroughly explored to host sulfur in current studies. Common methods for complexing the elemental sulfur with a porous host material mainly include melt infiltration, in-situ electro-deposition and chemical deposition, which are cumbersome in the preparation process and restrict the industrial development of the lithium-sulfur battery. For example, in the fabrication process of melt infiltration method, the elemental sulfur and porous host material should be premixed by means of grinding and heated in a sealed container at 150-160° C. under the protection of an inert atmosphere for 12-24 hours. After the temperature return to room temperature, sulfur composite cathode material is obtained. However, it is difficult for this method to achieve the requirements of industrialization due to its complicated procedures, high energy consumption, and long time period.